RFR: 8271356: JDB: GDB-style command repetition and `list` auto-advance

[Jakob Cornell]

This has been under discussion on and off for the past month or so on serviceability-dev, and I think a CSR request is required, so this may be a work in progress.

Notes on the patch:

- The `list` command previously marked a line in each listing with `=>`.  In a bare `list` this is the next line up for execution.  Previously when requesting a specific location (e.g. `list 5`) the requested line would be marked.  With the patch applied, `list` will only ever mark the next line up for execution.  This is consistent with the behavior of GDB and PDB (at least).
- `EOF` is printed when the repeat setting is on and a bare `list` command follows a listing containing the last source line.  This feature is from PDB; it's a somewhat softer message than the one for an explicit `list` request that's out of range.
- I don't speak Chinese or Japanese, so I've omitted localizations for the new messages in those locales.  However, I updated the help text in both to include the new commands, with the descriptions left empty for now.

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Commit messages:
 - 8271356: JDB: implement GDB-style command repetition and `list' auto-advance

Changes: https://git.openjdk.java.net/jdk/pull/5289/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5289&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271356
  Stats: 336 lines in 5 files changed: 107 ins; 20 del; 209 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5289.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5289/head:pull/5289

PR: https://git.openjdk.java.net/jdk/pull/5289